Electrical switch



June 4, 1940. o. FROLAND ELECTRICAL swn'ca Filed NOV. 27, 1939 4SheetsSheet 1 3 EM w o A Z M 5 a m A W m Y O r .I. O M Y R 3 NM 8 mm NS3 mm Fl! u R Wm -VW w g a w hm MQ nix Km m6 4 Sheets-Sheet 2 June 4,1940. o, FROLAND ELECTRICAL swncn F iled Nov. 27, 1939 4 Sheets-Sheet 5MN. & M M

June 4, 1940. Q R L D ELECTRICAL SWITCH Filed NOV. 27, 1939 mmswroz/ 0mv fem/4N0 Y A TTOE/YIE'Y Patented June 4, 1940 UNITED STATES PATENTOFFICE 2,203,351 ELECTRICAL swrron Olav Froland St. Louis, Mo., assignorto James It. Kearney Corporation, St. Louis, Mo., a corporation ofMissouri mentioned which includes improved means for.

operating the blade of the switch so that its movement may be undercomplete control at all times during movement thereof into and out ofthe closed switch position.

Fig. 1 is a side elevation of the improved switch with the lower portionof the operating element of the switch broken away.

Fig. 2 is an enlarged fragmentary plan View of a portion of the switchwith parts thereof shown in section.

Fig. 3 is a view partly in side elevation and partly in vertical sectionof the portion of the switch illustrated in Fig. 2.

Fig. 4 is a vertical fragmentary section taken on line 44 of Fig. 3 andlooking in the direction indicated by the arrow.

Fig. 5 is a view similar to Fig, 3 but showing parts of the switchstructure in the positions which they assume when the switch is in theopen switch position.

Fig. 6 is a view partly in side elevation and partly in vertical sectionof a portion of the operating mechanism of the improved switch.

Fig. 7 is an enlarged, fragmentary plan view of the portion of theswitch at which the contacts are located showing said contacts as theyappear when the switch is in the closed switch position.

Fig. 8 is a fragmentary View partly in vertical section and partly inelevation of the part of the switch illustrated in Fig. 7.

Fig. 9 is a fragmentary vertical section taken on line 9-9 of Fig. 8.

Fig. 10 is a view similar to Fig. 7 but showing contacts of the switchin contracted positions.

In the drawings, wherein is shown for the purpose of illustration,merely, one embodiment of the invention, I designates the base of theimproved switch, said base preferably, though not necessarily being madeup of a pair of spaced channel beams 2 suitably connected together toprovide a frame. The switch base I is adapted to be supported bysuitable supporting means to locate the switch in a desired position foruse,

Secured to the base I and extended upwardly therefrom is a supportingmember 3 which supports a stationary insulator 4. The insulator l 5' hasfixed thereto at its top a member 5 which at its forwardend is providedwith a horizontal wall 5a through which suitable fastening devices 5bare extended for the purpose of securing the member 5 to the insulator4. The member 5 is provided with spaced apart side Walls 6 which projectupwardly from the horizontal wall 5a and extend horizontally in arearward direction. The extreme rearward portion of the member 5 isprovided with a solid top wall i and forwardly of this solid top wallthe member 5 is provided with relatively narrow, horizontal top flanges8 which extend inwardly toward each other from the side walls of themember. Extended transversely of the member 5 between the flanges 8thereof is a pair of transverse bars 9 which aid in imparting therequired structural strength to said member 5.

Supported by and fixed to and between the spaced channel members of thebase i is a hearing member I0, the construction of which is shown to thebest advantage in Fig. 6. Disposed vertically and extended through thebearing member ID is a rotary spindle II which constitutes a downwardcontinuation of a connecting element I2. cludes complementaryrectangular shoulders I3 and the bearing member I0 is provided withsimilar shoulders I4, and interposed between the shoulders of thespindle and the shoulders of the bearing member is an annular ballbearing as- S.

sembly I5. Likewise at its lower end the hearing member Ill is providedwith complementary rectangular shoulders I6 and a ball bearing assemblyI1 is interposed between these shoulders and a raised annular face I8 onthe spindle H.

The ball bearing assembly I! is supported from thebottom by a jamb nutI9 which is mounted on a screwthreaded portion 20 of the spindle and ispinned thereto. Secured to the lower end portion of the spindle I I, bymeans of a suitable coupling element 2|, is an operating element 22,said operating element being adapted to rotate the spindle with respectto the bearing member and the ball bearing assemblies serving to reducefriction during such rotation of the spindle. its upper end the spindleII is provided with an annual hood 23 which overlies and covers theupper end of the bearing member I i].

Mounted on and secured to the connecting element I2 by means offastening'elements 24 is an insulator 25 which rotates with the spindleII and the connecting element I2. Extended upwardly from the upper endof the insulator 25 is a spindle 26 (Fig. 3) which passes through abearing member 21 that forms a part of the solid top The spindle II atits upper end in- ,J'

wall portion 1 of the member 5 heretofore described. The bearing 21 isprovided with complementary rectangular shoulders 28 which support aball bearing assembly 29, said ball bearing assembly contacting alsowith a raised, annular face 39 formed on the spindle 26. The ballbearing assembly 29 is maintained in position by an annular flange SI ofa member 32, said member being mounted on and pinned to a screwthreadedportion 33 of the spindle 26 and being so shaped and arranged that itoverlies and closes the upper end of bearing member 27. The extremeupper end portion 34 of the spindle 26 is preferably non-circular inhorizontal section and this spindle portion has clamped or otherwisesecured to it an arm 35.

Pivoted to the member 5 through the instrumentality of a pivot element36 is a movable switch arm which is designated generally by thereference character 37. The switch arm 31 includes a rear portion 39provided with a forward clamping portion 39 from which rearwardly eX-tended, spaced apart portions 46 are projected. The rear end portions ofthe spaced apart portions 46 of the arm portion 38 incline downwardly asillustrated in Fig. 3 and these inclined portions are provided withopposed hub portions 4!, arranged therebetween, through which the pivotelement 36 passes. At the opposite sides of the rear portion 38 of theswitch arm 31 coil springs 42 are attached to the spaced portions 49through the instrumentality of pins 43, which extend from boss portions43 formed on the spaced portions 46 of the portion 38 of the switch arm57. The portions of the coil springs 42 at the ends of said coil springsremote from the end thereof which are attached to the pins 43 areattached to the forward end portions of rods 44', which at their rearends are pivotally attached by means of pivot pins 44 to boss portions45 which are extended from the member 5. At the forward ends of the coilsprings 42 heads 46 are provided which are pivotally connected to thepivot pins 43 as shown to the best advantage in Fig. 2. These heads 46include hollow forward portions 41 through which the forward extensionsof the coil springs extend, and enlarged sleeve portions 48 at the rearends of said heads which screw-threadedly receive tubular elements 49that embrace the coil springs 42 and the forward portions of the pin 43.

In order to provide for good electrical con tact between the member 5and the switch arm 3'! a plurality of pairs of resilient rods 56 areemployed. These resilient rods are supported by members 55 which aresecured to the side walls 6 of the member 5 (Fig. 3) and extend upwardlytherefrom into contact with the hub portions 4! and because the upperend portions of the rods 55 tend to move toward each other closeelectrical contact between said rods and the hub portions 4| will beobtained.

The forward portion of the switch arm 3'! in-- cludes a tube 5! whoserear end portion is en gaged by the clamping portion 39 of the rearportion of the switch arm previously described herein, said tube beingextended forwardly from said clamping portion 39 and being internallyscrewthreaded at its forward end as shown at 5| in Fig. 8. At itsforward end the tube 5! has attached thereto an end member 52 which isprovided with a screwthreaded extension 52 which is screwed into andpinned to the screwthreaded forward portion of the tube 5!. The endmember 52 is hollow and is provided with an end wall 53 through which anopening is formed, said end member being provided also with an extension54 which projects downwardly and forwardly from said end member as shownto the best advantage in Fig. 8 and is provided with oppositely extendedflanges 54' at its forward end to provide said extension 54 with a broadforward face (Fig. 9).

Extended horizontally in opposite directions from the end member 52 arerigid extensions 55 each of which has formed thereon an upwardly and adownwardly extended bearing 56, each extension 55 and its associatedbearings 56 having a continuous opening formed therethrough from top tobottom. Pivoted to each extension 55 is an arm structure 51 whichcomprises a pair of vertically spaced arms 51a which are rigidlyconnected at the approximate longitudinal center of the arm structure byan integrally formed bar 51?). Pivotal connection between rear ends ofthe arm structures 5'! and the extensions 55 is obtained by means ofvertical pins 58 which are retained in place by cotter pins orotherwise.

The tube 5! has extended longitudinally thereof a tube 59 of smallerdiameter and secured to this tube 59 at its forward end is a head 69.When viewed in side elevation the head 66 includes a vertically disposedportion 6911 which has an opening formed longitudinally therethrough anda shorter horizontal portion 601) which projects from the approximatelongitudinal center of the portion 69a. The outer face of the portion69b abuts against the forward face of the tube 59 and this portion 691)has extended therefrom a stud 690 which is disposed within the forwardportion of the tube 59. In order to secure the head 69 to the tube 59 apin 6! is extended through alined openings formed in opposed portions ofthe tube and in the stud 69o.

Associated with the head 69 is a pair oflink structures 62, each ofwhich includes a vertical portion 62a from which is extended a pair ofrigid substantially parallel arms 62?) (Fig. 9). The inner, adjacentends of the arms 62b of the link structures 62 are pivotally connectedto the head 60 by a vertical pin 63 which passes through alined openingsin the associated pairs of arms 62b and in the vertical portion 60a ofthe head 69, it being noted from an inspection of Fig, 9 that the armsof the opposed link structures are so located with respect to each otherthat their end portions overlap so as to bring the alined openings ofthe arms into alinement with each other and with the opening formedthrough the portion 69a of the head. Because of this a1- rangement it isobvious that the arms of the link structures 62 are pivotally attachedto the head 60. The vertical portions 62a of the link structures are inturn pivotally attached to the forward end portions of the armstructures 51. such pivotal attachment being obtained through the use ofvertical pins 64 which pass through alined openings formed through theforward end portions of the arms 51a of the arm, structures and throughopenings formed in the portions 62a of the link structures, whichportions 62% are interposed between said arms 51a of the arm structures51.

At its rear end the tube 59 has fixedly attached thereto a member 65which is bifurcated at its rear end. The bifurcated portion of themember 65 has pivoted thereto through the instrumentality of a pivot pin66 a link 61, the intermediate portion of said link being disposedbetween the spaced legs of said bifurcated portion and the pivot pin 66being extended through al-ined openings formed in the legs of thebifurcated portion and through said intermediate portion of the link.The lower portion of the link 61 is arranged in screwthreaded engagementwith an element 58 which is pivoted between the spaced portions 44 ofthe rear portion 38 of the switch blade 31, a pivot pin 69 serving toprovide the pivotal attachment of said element. The link 61 includesalso an upper portion which projects upwardly beyond the point at whichthe member 95 is connected to said link.

. Associated with the link 61' is a member 19' which is supported forswinging movement by an arm ll anda pair of transversely spaced arms 12.The member Hi throughout most of its length is in the form of a bar 13and at the forward end of said bar the member '79 includes a bifurcatedportion 19 which is produced by laterally extended portions'lfi extendedoutwardly in opposite directions from said bar, and spaced apartportions 15 which extend upwardly and forwardly from said laterallyextended portions. The upper end portion of the link 61 is disposedbetween the spaced apart portions 16 of the member 10, and said upperend portion of said link is attached for pivotal movement to the memberIll by means of a pivot pin l1 which is disposed in alined aperturesformed through the upper portion of the link 9'! and through the spacedapart portions N of the member 19. The upper end portion of thearm H isbifurcated and the upper portions of the arms 12 are spaced apart, thebar'portions E3 of the member 1!! being disposed between the spacedupper portions of said bifurcated arm l! and between the spaced upperportions of said arms 12,'with pivot pins l8 and 79 pivotally connectingsaid upper end portions of said arms H and '12 to the bar portion ofsaid member Hi. The lower portion of the arm 1! is pivoted, by means ofthe pivot element 3B hereinbefore mentioned, between the spaced portions89 of the upper bifurcated portion of a support 89 which extendsupwardly from the horizontal wall 5a of the member 5 (Fig. 4). The lowerportions of the arms 12. are pivotally attached to the member 5 by pivotelements 8!.

Disposed between the spaced portions 16 of the bifurcated portion I l ofthe member 10, and pivoted thereto by means of a pivot pin 82, is acoupling element 83, said coupling element ineluding a portion which isdisposed between spaced portions 84 of the forward bifurcated portion 84of a connecting element 85, and which is pivoted to said spaced portions84' by a pivot pin 86. At the rear end of the connecting element 85 amember 81 is clamped or otherwise secured thereto, and this member 81 ispivoted by means of a pivot pin 88 to an element 89 which in turn ispivotally attached to the outer end of the arm 35 by means of a pivotpin 90.

Secured to the base I of the switch is a supporting element 9i whichsupports a fixed insulator 92. The insulator has fixed to it a member 93which includes an upwardly and forwardly extended portion 93 which isprovided with a solid top wall from which a vertical extension 84 isprojected. The vertical extension 94 has anchored therein a' contact 95which is 001m prised of a plurality of relatively heavy parallel wireswhich when viewed in plan are bent in approximately U-shape as shown inFigs. '7 and 10. The wires of which the contact 95 is composed arepossessed of resiliency so that when the rearwardly extended legsthereof are spread apart said legs will return to their originalconditions when the force which spread them is removed.

The member 93 is provided with abuffer 96 which comprises a headed pinsupported for vertical movement by a bearing element 9"! forming a partof the member 93, said headed pin having a coil spring 98 associatedtherewith which urges same in an upward direction. The coil spring 93 isinterposed between the under face of the head. of the buffer and the topface of the bearing element 91, and a cotter pin 99 is employed to limitupward movement of the buffer in response to expansive action of thecoil spring. When the switch arm 31 is lowered from the raised positionin which it is shown in Fig. 5 to the'lowered position in which it isshown in Fig.1. the extension 54 of the end member 52 and said switcharm strikes the head of the buffer and. the coil spring of the bufferabsorbs the shock incident to the sudden stoppage of the downwardmovement of the switch arm. Also the member 93 supports an arcing hornI09 which functions in an obvious manner as the broad face at the end ofthe extension 59 moves into and out of contact therewith when the switcharm 3! is moved into and out of the closed switch position.

The improved switch is provided'with a terminal In! which is fixed tothe rear end portion of the member 5, and a similar terminal H12 whichis fixed to the member 99. These terminals have secured to themconductors C forming parts of the electrical line in which the switch isinterposed.

In explaining the operation of the improved switch it will be assumedthat the switch is in the open switch position, as shown in Fig. 5, andthat it is desired to operate the switch to cause it to assume theclosed switch position as shown in Fig. 1. Such operation of the switchis pro duced by the person operating it rotating the operating element22 so as to impart like rotary movement to the assembly of parts made upof the spindles II and 26, the member l2 and the insulator 25 andthereby swinging the arm 35 in an arc of a circle. As rotary movement isimparted to the arm 35 as described forward acting force is imparted tothe switch arm 3'! through the connecting assembly which includes theelement 89, the connecting element 85, the coupling element 89, themember 10, the link iii, and the arms H and 12. It is to be noted thatat the time the forward and downward movement of the switch arm. isstarted the link 5'! is extended in substantial parallelism with respectto the connecting element 85, as shown in Fig. 5, and therefore force isdirected longitudinally through said link 6! to the pivot pin 69 whichis carried by a part of the switch arm 3'! until said switch arm reachesan overbalanced position from which it will move by gravity to itslowered position. As movement of the arm 35 continues toward theposition in which said arm 35 is shown in Fig. 2 the switcharm movestoward its lowered position, saidmovement of the switch arm beingcontrolled by the person operating the switch restraining rotation ofthe operating element 22, and eventually the switch arm 3? reaches itslowered position where the extension i l at the forward end of theswitch arm contacts with and restsupon the buffer 96.

During downward movement of the switch arm toward its lowered positionthe link 61 is subjected to pivotal movement about the pivot pin 99 inthe direction of the arrow in Fig.5 which results in the tube 59 beingmoved rearwardly of the switch arm. The result of such rearward movementof said tube 59 is that the head 69 at the forward end of said tube 59is likewise drawn rearwardly as shown in Fig. 10. Also with the head 69drawn rearwardly the link structures 62 assume the contracted positionsin which they are shown in Fig. 10 and the arm structures 51 which arepivoted at their forward ends to the link structures 62 are drawn to thecontracted and convergent positions in, which these arm structures areshown in Fig. 10.

When the switch arm 31 reaches its lowered position in contact with thebuffer 96 the link structures 62 and the arm structures 51 are in thecontracted positions described and a portion of the arcuate stroke ofthe arm 35 still remains to be traversed. During this additionalmovement of the arm 35 the tube 59 is moved forwardly with respect tothe switch arm 37 and such forward movement of the tube 59 results inlike forward movement of the head 69 which moves the link structures 62and the arm structures 51 to the expanded positions in which they areshown in Fig. 7. This forces the portions 62a of the link structures,which serve as contacts of the switch, into close electrical contactwith the opposed portions of the contact 95, spreading said opposedportions of said contact 95 to insure the desired close electricalcontact. When the contact has been made between the portions 62a of thelink structures 52 and the opposed portions of the contact 95, the tube59 is held in its forward position by the locked condition of the to gleproduced by the arm 35 and the assembly of which the connecting elementforms a part. Also the head 69, link structures 52 and the forwardportions of the arm structures 51 provide a toggle structure which islocked when the portions 62a of the link structures are expanded intocontact with the opposed portions of the contact 95.

When the switch arm 31 is to be drawn upwardly and rearwardly from theclosed switch position to the open switch position the sequence ofoperations just described are reversed. That is to say the initialportion of the arcuate stroke of the arm 35 from the position in whichsaid arm is shown in Fig. 2 toward the position of said arm asillustrated in Fig. 5 moves the tube 59 and the head 69 rearwardly todraw the portions 62a of the link structures 62 inwardly away from theopposed portionsof the contact to their contracted positions as shown inFig. 10. Continuation of such movement of the arm 35 results in theswitch arm 39 being swung upwardly about the pivot 36 to its raised openswitch position as shown in Fig. 5. In connection with the action ofraising the switch arm 37 to elevated open switch position it is pointedout that the coil springs 42 (Fig. 2) serve to counterbalance the weightof the forward portion of the switch arm. In other words the coilsprings 42 are under tension and as the upward movement of the forwardportion of the switch arm is started the coil springs 42 exert arearward pull on the lower end of the switch arm above the pivot element36 which assists an operator to raise the switch arm. Likewise thepresence of the coil springs 42 prevents the forward end portion of theswitch arm from being dropped down with violence when the switch arm islowered as the gradually increased tension which is built up in the coilsprings as the forward end of the switch arm is lowered serves toprevent too rapid lowering of the switch arm.

When the portions 62a of the link structures 62 are expanded intocontact with the opposed portions of the contact 95 by forward movementof the head 60 at the forward end of the tube 59 said portions 62a arebeing rotated while contact is being made with said opposed portions ofthe contact 95. This produces a wiping action which serves to keep thecontacting faces clean and free from corrosion. Additionally the rotarymovement mentioned serves to break ice which may form under adverseweather conditions at the points where contact is made. In order toprovide for efiicient transfer of electrical energy to the positions 62aof the link structures groups of resilient rods I03 are provided whichare supported by the portions 51b of the arm structures 5! and contactwith considerable force with portions of the end member 52 and with saidportions 62a of the link structures. Also at the front ends of the lowerportions 51a of the link structures 5'! downward projections I94 areprovided which have curved faces I94 formed thereon (Fig. 9). Theseprojections serve as guides which facilitate movement of the forwardportion of the switch arm 3! between the spaced portions of the contact95 even though the switch arm should, for any reason, be thrown out of'1 proper alinement with respect to said contact 95.

The predominant feature of the present invention, and the feature whichdifferentiates the present invention from the invention disclosed inapplicants previous application identified above, has to do with theconnecting assembly which connects the switch arm 31 to the operatingarm 35. This assembly includes the member 70', the arms H and I2, andthe link 61 to which the tube 59 is connected by the pivot element 66,and becuase of the cooperative relation of the parts making up theconnecting assembly referred to, the tube 59 and the switch arm 31 aremaintained. under complete control at all times so that the action ofgravity may not interfere with the operation of the tube 59 and itsassociated parts regardless of the position in which the switch isdisposed.

I claim:

1. A switch mechanism comprising a switch arm supported for swingingmovement into and out of closed switch position, a stationary support bywhich said switch arm is movably supported, a stationary contact, acontact assembly supported by said switch arm and adapted for T movementindependently of said switch arm into and out of electrical contact withsaid stationary contact, and means for swinging said switch arm intoand. out of closed switch position and for moving said contact assemblyinto and out of electrical contact with said stationary contact, saidmeans comprising a member supported for pivotal movement by saidsupport, a link pivoted to said switch arm and to said member, anelongated operating element pivoted to said link and associated withsaid contact assembly for moving said contact assembly, and operatingmeans for subjecting said member to pivotal movement.

2. A switch mechanism comprising a switch 7 arm supported for swingingmovement into and out of closed switch position, a stationary support bywhich said switch arm is movably supported, a stationary contact, acontact assembly supported by said switch arm and adapted for 7 movementindependently of said switch arm into and out :of electrical contactwith said stationary contact, and means for swingingsaid switch arm intoand out of closed switch position and for moving said contact assemblyinto and out of electrical contact with said stationary contact, saidmeans comprising a member supported for pivotal movement by saidsupport, a link pivoted to said switch-arm and to said member, anelongatedoperating element pivoted to said link at a point intermediatethe points at which said link is pivoted to said switch arm and to saidmember and associated with said contact assembly for moving said contactassembly, and operating -means for subjecting said member to pivotalmovement. I

3. A switch mechanism comprising a switch arm supported for swingingmovement into and out of .closed switch position, a stationary sup- 20movement independently of said switch arm into and out of electricalcontact with said stationary contact and. means for swinging said switcharm into and out of closed switch position and for moving said contactassembly into and out of electrical contact with said stationarycontact, said means comprising a member supported for pivotal movementby said support, a link pivoted at one of its ends to said switch arm:and pivoted at its opposite end to said member, an elongated operatingelement pivoted to said link at a point intermediate the pivoted ends ofsaid link and cooperatively associated with said contact assembly formoving said contact assembly, and operating means for subjecting saidmember to pivctal movement.

4. A switch mechanism comprising a switch arm supported for swingingmovement into and out of closed switch position, a stationary support bywhich said switch arm is movably supported, a stationary contact; acontact assembly supported by said switch arm and adapted for movementindependently of said switch arm into and out of electrical contact withsaid stationary contact, and means for swinging said switch arm into andout of closed switch position and for moving said contact assembly intoand out of electrical contact with said stationary contact, said meanscomprising a member, an arm pivoted to said support and to said memberwhereby said member is supported for pivotal movement by said support, alink pivoted to said switch arm and to said member, an elongatedoperating element pivoted to said link and associated with said contactassembly for moving said contact assembly, and operating means forsubjecting said member to pivotal movement.

5. A switch mechanism comprising aswitch arm supported for swingingmovement into and out of closed switch position, a stationary support bywhich said switch arm is movably supported, a stationary contact, acontact assembly supported by said switch arm and adapted for movementindependently of said switch arm into and out of electrical contact withsaid stationary contact, and means for swinging said switch arm into andout of closed switch position and for moving said contact assembly intoand out of electrical contact with said stationary contact, said meanscomprising a member, a pair of arms pivoted to said support and to saidmember whereby said member is supported for pivotal movement by saidsupport, a. link pivoted to said switch arm and to said member, anelongated operating element pivoted to said link and associated withsaid contact assembly for moving said contact assembly,andoperatingmeans for subjecting said member to pivotal movement.

6. A switch mechanism comprising a switch arm supported for swingingmovement into and out of closed switch position, a stationary support bywhich said switch arm is pivotally supported, a stationary contact, acontact assembly supported by said switch arm and adapted for movementindependently of said switch arm into and cut of electrical contact withsaid stationary contact, and means for swinging said switch arm into andout of closed switch position and for moving said contact assembly intoand out of electrical contact with said stationary contact, said meanscomp-rising a member, an arm pivoted to said support and to said memberwhereby said member is supported for pivotal movement by said support, alink pivoted at one of its ends to said switch arm and pivoted at itsopposite end to said member, an elongated operating element pivoted tosaid link at a point intermediate the pivoted ends of. said link andcooperatively associated with said contact assembly for moving saidcontact assembly, and operating means forsubjecting said member topivotal movement.

"7. A switch mechanism comprising a switch arm supported for swingingmovement into and out of closed switch position, a stationary support bywhich said switch arm is 'pivotally supported, a stationary contact, acontact assembly supported (by said switch arm and adapted for movementindependently of said switch arm into and out of electrical contact withsaid stationary contact, and means for swinging said switch arm into andout of closed switch position and for moving said contact assembly intoand out of electrical contact with said stationary contact, said meanscomprising a member, a pair of arms pivoted to said support and to saidmember whereby said member is supported for pivotal movement by saidsupport, a link pivoted at one of its ends to said switch arm andpivoted at its opposite end to said member, an elongated operatingelement pivoted to said link at a point intermediate the pivoted ends ofsaid link and cooperatively associated with said contact assembly formoving said contact assembly, and operating means for subjecting saidmember to pivotal movement.

8. A switch mechanism comprising a switch arm supported for swingingmovement into and out of closed switch position, a stationary support bywhich said switch arm is pivotally supported, a stationary contact, acontact assembly supported by said switch arm and adapted for movementindependently of said switch arm into and out of electrical contact withsaid stationary contact, and means for swinging said switch arm into andout of closed switch position and for moving said contact assembly intoand out of electrical contact with said stationary contact, said meanscomprising a member, a pair of arms pivoted to said support and to saidmember whereby said member is supported for pivotal movement by saidsupport, said switch arm and one of said pair of arms being pivoted tosaid support at a common point, a link pivoted at one of its ends tosaid switch arm and pivoted at its opposite end to said member, an

- elongated operating element pivoted to said link at a pointintermediate the pivoted ends of said link and cooperatively associatedwith said contact assembly for moving said contact assembly, andoperating means for subjecting said member to pivotal movement.

9. A switch mechanism comprising a switch arm supported for swingingmovement into and out of closed switch position, a stationary support bywhich said switch arm is pivotally supported, a stationary contact, acontact assembly supported by said switch arm and adapted for movementindependently of said switch arm into and out of electrical contact withsaid stationary contact and means for swinging said switch arm into andout of closed switch position and for moving said contact assembly intoand out of electrical contact with said stationary contact, said meanscomprising a member, a pair of arms pivoted to said support and to saidmember whereby said memberis supported for pivotal movement by saidsupport, a link pivoted at one of its ends to said switch arm andpivoted at its opposite end to said member, an elongated operatingelement pivoted to said link at a point intermediate the pivoted ends ofsaid link and cooperatively associated with said contact assembly formoving said contact assembly, and operating means for subjecting saidmember to pivotal movement, said operating means comprising a rotaryelement, an arm fixed to said rotary element for arcuate movement, andconnecting means for converting arcuate movement of said arm of theoperating means into pivotal movement of said member.

10. A switch mechanism comprising a switch arm supported for swingingmovement into and out of closed switch position, a stationary support bywhich said switch arm is pivotally supported, a stationary contact, acontact assembly supported by said switch arm and adapted for movementindependently of said switch arm into F and out of electrical contactwith said stationary contact, and means for swinging said switch arminto and out of closed switch position and for moving said contactassembly into and out of electrical contact with said stationarycontact, said means comprising a member, a pair of arms pivoted to saidsupport and to said member whereby said member is supported for pivotalmovement by said support, a link pivoted at one of its ends to saidswitch arm and pivoted at its opposite end to said member, an elongatedoperating element pivoted to said link at a point intermediate thepivoted ends of said link and cooperatively associated with said contactassembly for moving said contact assembly, and operating means forsubjecting said member to pivotal movement, said operating meanscomprising a rotary element, an arm fixed to said rotary element forarcuate movement, and connecting means for converting arcuate movementof said

